This invention relates to deposition of thin stable, adherent abrasion resistant films or coatings on various surfaces, particularly plastic surfaces and to articles having such coatings.
Engineering resins are well-known, commercially available materials possessing physical and chemical properties which are useful in a wide variety of applications. For example, polycarbonates, because of their excellent breakage resistance, have replaced glass in many products, such as automobile headlamps and stoplight lenses; safety shields in windows, architectural glazing, and the like. However, major defects exhibited by polycarbonates are their very low scratch-resistance and their susceptibility to ultraviolet light-induced degradation.
Several techniques for depositing silicon films are commonly employed such as chemical vapor deposition (CVD), physical vapor deposition(PVD), electron beam epitaxy and plasma enhanced chemical vapor deposition (PECVD) and plasma polymerization (PP). The choice of process is often dictated by the substrate to be coated especially the thermal stability of the substrate which limits the temperature to which it can be exposed. A primary goal is to deposit hard, wear resistant, silicon films on plastic for a variety of applications such as optical glass, architectural windows, automobile windows, and the like. Key to production of such products is the development of high rate low cost processes that can deposit a high quality oxide film on the surface, particularly on plastic surfaces. Physical vapor deposition techniques such as sputtering can yield good quality coatings but at low rates which are not cost effective. High temperature chemical vapor deposition techniques can yield high rates but at temperatures that exceed the temperature limit of the substrate.